The adult form of polycystic renal disease is inherited as an autosomal dominant trait. It is a slowly progressive condition which affects renal tubules, and is a common problem leading to end-stage renal failure. The cause of this disease is unknown; however, recent evidence implicates an abnormality in the basement membrane of the affected renal tubules. The proposed studies are designed to search for a defect by comparing normal and polycystic tubules: 1. An animal model of polycystic renal disease will be induced and individual nephron segments will be disected for microperfusion studies to determine their distensibility characteristics. These results will be compared to normal values in order to obtain clues to the nature of the basement membrane defect. 2. Preparative quantities of tubules from normal and diseased animals will be prepared, and their respective basement membranes will be compared. This comparison will involve a detailed electrophoretic analysis and determination of the chemical composition of normal and polycstic membrane.